Once upon a time in Kamchatka: the search for natural quasicrystals

Abstract

We present evidence for a naturally occurring quasicrystal consisting of micron-sized grains of Al₆₃Cu₂₄Fe₁₃ with icosahedral symmetry embedded in a sample of khatyrkite (nominally, (Cu,Zn)Al₂) obtained from the Khatyrka ultramafic zone of the Koryak Mountains in the northern half of the Kamchatka Peninsula.

Keywords:

• quasicrystals
• X-ray diffraction
• geological materials
• alloys
• aperiodic materials
• inorganic materials

Acknowledgements

We are indebted to P. Lu and N. Yao, who contributed significantly to 6,7 and many of the results reviewed in this paper. Also, L. Hollister and G. MacPherson have been collaborators in testing and developing formation theories. We would also like to thank C. Ballhaus, J. Beckett, P. Bonazzi, K. Deffeyes, J. Eiler, V. Distler, A. Ishiwatari, S. Menchetti, M. Morozov, P. Robinson, V. Rudashevkij, E. Stolper and P. Spry for useful discussions. LB thanks M.I.U.R., P.R.I.N. 2007 project “Complexity in minerals: modulation, phase transition, structural disorder” issued to Silvio Menchetti. This work in support in part by the National Science Foundation-MRSEC program through New York University (DMR-0820341; PJS).